docs(graphile-postgis): lead spatial-relation examples with ORM where: shape

[pyramation]

Summary

Docs-only follow-up to #993. The README for @spatialRelation previously only showed GraphQL filter: examples, but most consumers use the generated ORM (where:). This adds ORM-shaped examples above each GraphQL example so readers can copy the form that matches their layer.

Also fixes a stale eq → equalTo in the GraphQL examples (the graphile-connection-filter idiom is equalTo; this is the same fix applied to the test suite in #993).

Review & Testing Checklist for Human

• Confirm the ORM snippets (orm.telemedicineClinic.findMany({ where: { … } }).execute()) match your preferred documentation style — they mirror the shape used in the E2E test at graphql/orm-test/__tests__/postgis-spatial-relations.test.ts but the README isn't executed, so typos would go unnoticed.
• Skim-render the README on the PR page to check the two layers (where: ORM block → filter: GraphQL block) read cleanly in sequence.

Notes

No code changes, no new tests; CI will just run the existing suite. Zero expected behaviour change.

Link to Devin session: https://app.devin.ai/sessions/c5eeee65a3c546c4ac6753bb05fa03e0
Requested by: @pyramation

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